Need help fitting LCAs

[JeffS]

I have several issues with how my front control arms fit on my chassis (#051) and need some advice...

First, the front bushing does not fill the space where it sits between the mounting plates. There is about 0.15 inch of axial play in the front bushing. The engineer in me wants to insert a spacer so that the inner sleeve of the bushing is held tight by the front mounting bolt. Should the spacer go in front of, or behind the front bushing? This affects the position of the lower ball joint so there should be just one answer.

My rear mounting points are completely off the mark as well. Upper holes don't align with lower holes on the same bracket, and the rear bracket in general does not align with the front bushing. Re-drilling will be required to get everything aligned.

Does anyone know what the ball joint position should be from the SolidWorks model?

If I use the front holes to position the front bushing and just assume they are close enough, then the only dimension I really need is the spacing between the control arms at the rear bushings so that I can re-drill the rear brackets in the right place.

Any advice would be appreciated.

Thanks... Jeff

[Bill Waters]

Hi, Jeff;

I have some questions. The first one is whether the two tabs between which the front bushing on the LCA fits are parallel. These will occasionally be splayed due to weld warp etc., and, in tightening the bolt, are brought into proper parallel registry relative to the ends of the inner, steel part of the bushing. The ones on my 818 are all parallel, but those on the subframe of my LS3-into-Mazda Miata subframe, as well as my FFR roadster, were not. The second question is whether you are sure the LCA rear bushings are flipped as they are supposed to be. Mine did not appear to be aligning with the mounting holes when I first fitted them, but it turns out they were fine.

Does putting the spacer in front or behind the front bushing make the rear bushing mounting holes line up? If so, I'd go with that one, since the effect on anything but caster would be negligible and caster is entirely adjustable.

Realize that the spacer should have an internal diameter just slightly larger than the ID of the inner sleeve of the bushing. What holds everything in place and ensures proper function is the compression fit between the inner sleeve and the mounting tabs or, in your case, the spacer sandwiched between the tab and the inner sleeve.

Don't know if this helped, but hope so.

Bill

[JeffS]

Thanks Bill:

Since I am using 2006 WRX aluminum arms I went with the lower inner holes in the front, which I assume would pair up with the inner holes in the rear bracket. The rear bushings are flipped but that still leaves two possible orientations and the "ears" of the rear bushing are not symmetrical. The SolidWorks layout in my manual shows the "flat" ear up and the "grooved" ear down, so that is how I tried fitting them.

I think that the "welding warp" you described is the problem both in the front and the back. The front two tabs are not quite parallel, but even if they were pulled parallel with the mounting bolt I would still need a substantial spacer. I think that the welding movement of the front plates has skewed the pointing direction of the front bolt and that is causing the misalignment at the back.

I could just assume that the back mounts are close enough to correct and re-drill the holes for the front bushing, except that each rear bracket is misaligned from the top mounting surface to the bottom surface. In other words.... even if I completely ignore what is happening at the front bushing, there is no position of either rear bracket that aligns both the upper and lower hole simultaneously. Thus I am back to asking the question of what is the proper spacing between the rear bushings. Then I could (maybe) pick the hole on each rear bracket (upper or lower, inner or outer) that comes closest to giving me the right spacing per the 3D model and drill out the other hole to complete the mounting. I guess I'll try calling the guys at the factory tomorrow.

Jeff

[RM1SepEx]

Jeff, the "wiggle" in the arm is on the bottom, yes use the inner holes, the upper tang with the flat fits under the frame bracket

http://thefactoryfiveforum.com/showt...d-Thread/page3 see post 95

we had all kinds of issues with early frames, this area of my thread will help. We had to clearance the vertical portion of the bracket a wee bit.

[JeffS]

Thanks Dan:

I made about 30 measurements on the front of my frame last night. Within my measurement accuracy of about 2mm I have to admit that my frame is amazingly straight, square, and symmetrical. The one area where a little error has crept in is in the mounting holes for the LCA front bushings. Those bolt holes are a little out of alignment, but because of the distance to the back bracket make the back bushing holes way off. I decided to re-drill the front bolt holes using the front bushing of the LCA as a drill guide, and with the rear bushing clamped in place at the rear bracket.

Using a straight piece of pipe across the front of the chassis my lower arms measure the same distance back from the pipe at the lower ball joint, and there is no binding in the bushings with everything tightened up.

Thanks again... Jeff

[RM1SepEx]

Mine had a slight bind in the bushings, I'm going to live with it! I tried for months to get a dimension from FFR... crickets... I used a straight dowel to verify that everything was square... I measured everything, as with you mine is as square and true as possible to measure with my equipment

[Bob_n_Cincy]

Jeff
I had to enlarge the holes in my frame. See my picture.
I have wagon LCA's
Bob
P1040604s.jpg

[wleehendrick]

Jeff
I had to enlarge the holes in my frame. See my picture.

Same here... my driver's side lined up fine, but I had to open up one hole on the passenger's side to allow the bolt to pass through.

[Bill Waters]

I'm afraid that these are the vagaries we face as (involuntary) beta-testers! My front LCAs (like others who have posted this dimensional issue) hit the frame when mounted in the upper back mounting holes (I have an R). After clearancing by removing casting flash, I still only have about .020" clearance.

Sounds like you prevailed,, Jeff!

Bill

[Dr1v3Fa2T]

I have the same issue with the front bushing. Replaced my steel LCAs with Aluminum but the issue seems to be that the total width of the mounting points is miles too large for the front bushings. The width of the bushings seems to be the same between the steel and Al arms. The manual makes no mention of using spacers and the pictures don't show such a large discrepancy. My guess is that because everyone from Beta builds seemed to have trouble with the rear mounting positions so FFR left tones of room in there. I guess spacers are in order or several washers as in my case there is space on both sides not just one when the rear bush is mounted in place.
Would have been nice to have a note in the manual saying you need to space your front bushings accordingly...